The subject matter of the present invention relates to an apparatus for sealing a well casing, and more particularly, to a multiple cup stuffer through tubing bridge plug for sealing a perforated well casing when hydrocarbon well fluids cease to flow from the perforated casing.
When a well casing is perforated, hydrocarbon fluids flow from the perforated casing. Frequently, a particular formation, from which hydrocarbon fluids had previously been flowing, ceases to flow the desired hydrocarbons, but rather undesired fluids, such as water, begin to flow into the casing. If another formation exists adjacent the casing, such formation being located above the first formation which is now flowing the undesired fluids, the casing is sealed above the first group of perforations. Thereafter, the casing is again perforated along its length adjacent the second formation from which hydrocarbon fluids are desired to be produced. A sealing apparatus is normally suspended by wireline, the sealing apparatus sealing the casing above the first group of perforations. One such sealing apparatus is disclosed in U.S. Pat. No. 4,554,973 to Shonrock, et al, assigned to the same assignee as that of the present invention. The Shonrock sealing apparatus is an elastomeric sealing element for a bridge plug; however, due to its appearance, it is commonly known as a "football". The shonrock football sealing apparatus possessed a low temperature rating relative to the current needs of the logging industry. In addition, the football is expensive to manufacture. Furthermore, if it is necessary to seal a well casing, it is desirable to use the same sealing apparatus for different sized well casings. However, it is very difficult if not impossible to manufacture the football sealing apparatus in larger sizes Therefore, it is very difficult if not impossible to use the Shonrock football sealing apparatus for different sized well casings.